The invention relates to a shelf system with support rods and shelf boards which include fastening devices for fastening to the support rods at different heights.
Typically, the support rods are combined to form support frames which are arranged in the right and left corner regions of the rectangular shelf boards. Holes are arranged at various heights on the support rods. Fastening elements, such as support pins, which hold the shelf boards at the different heights can be inserted into these holes.
The French Patent No. 480 614 describes a shelf system with shelf boards that do not include fastening devices. Instead, the shelf boards are placed on a transversely extending traverses which include at their respective ends a pair of curved gripping jaws that can be pressed together with screws. To support one shelf board, two traverses have to be placed between each pair of support rods. Consequently, each shelf board is supported by four rods extending in the respective corner regions of the shelf board. The shelf board is quite difficult to install since for each board two traverses have to be secured to two support rods with two clamps each and adjusted in height.
The French Patent No. 1 524 363 describes a shelf system wherein each shelf board has on each of its four corners, i.e., in the end regions of the respective opposite end faces, a fastening device with a pair of curved gripping jaws that can be pressed together with screws. This reference essentially discloses the preamble of claim 1. However, attaching the board is still complicated since four pairs of clamping surfaces have to be pushed onto four support rods and clamped on these support rods.
It is an object of the invention to provide a novel shelf system wherein the height of the shelf boards can be continuously adjusted and wherein the position of the shelf boards of adjacent shelf sections can be adjusted within a predetermined angular range.
The object is solved by the invention in that the support rods have the form of cylinders and that each shelf board includes a fastening device arranged in the center of the two end faces of the shelf board. The fastening device consists of a pair of parallel clamping rods which project from the end face. The clamping rods are connected to each other by a clamping screw which pulls the two clamping rods toward each other, wherein one support rod is clamped between each pair of clamping rods.
With this type of clamping system which does not include bores and support pins for attaching the shelf boards, the shelf boards can be clamped to the support rods at any height. Because the cylindrical support rods have a round cross-section, the shelf boards can radially extend from the support rods in any direction and be clamped to the support rods in any position.
With the shelf system of the invention, the shelves can be installed in many ways. For example, a central support rod can be provided from which several (for example, three or five) shelf sections extend radially outwardly, forming a star. Each shelf section is associated with an outer support rod to which the outside end faces of the shelf boards are clamped. It is also possible to provide long shelf units consisting of several consecutive sections, wherein the center axes of the shelf boards of consecutive shelf sections extend along an arbitrary polygonal path. This design of a shelf unit can be readily adapt to fit, for example, a curved building wall.
The inside surfaces of the clamping rods which contact the cylindrical support rod, should be as straight as possible, so that they can be easily pushed over the circumference of the support rod. In this way, a shelf board can be attached to or removed from an installed shelf at any position. This is more difficult when the gripping jaws are curved. It may be necessary to first release one clamping rod completely from the shelf board and to then reattach this clamping rod after the support rod has been inserted into the curved surface of the other clamping rod. Alternatively, the shelf board may be inserted from above by pushing the support rod into the opposing curved surfaces of the two clamping rods. Consequently, clamping rods with straight inside surfaces provide the simplest installation for the shelf board. The surface of the clamping rods which is oriented outwardly from the support rods, can have any shape.
Preferably, the clamping rods located on opposite end faces of the shelf boards are offset from each other by a distance corresponding to the height of the clamping rods. For example, the clamping rods disposed on the right end face of the shelf boards may be inserted in the upper half of the shelf board, whereas the clamping rods disposed on the left end face may be inserted in the lower half. Shelf boards of adjacently positioned shelf sections can thereby be arranged in the same plane. The clamping devices attached to the same support rod are offset from each other so as not to interfere with each other.
The clamping screw is advantageously arranged between the end faces of the shelf boards and the support rods. Positioning the clamping screw on the side of the support rods opposite from the end faces may make it difficult to arrange the shelf boards side-by-side in the same plane. In order to arrange the shelf boards side-by-side and at the same height, the free ends of the clamping rods projecting beyond the clamping screws are preferably shorter in length than the diameter of the support rods. The free ends then do not extend beyond the support rods and do not make contact with the adjacent shelf board. The free ends have to be at least as long as the radius of the support rods, so that the clamping rods can clamp the support rod along two outer surface lines of the support rod.
The clamping process is facilitated by providing one of the clamping rods of a clamping rod pair with a through-bore for the clamping screw and the other clamping rod with a threaded bore. The screw head of the clamping screw abuts the first clamping rod on the other side of the through-bore and pulls the first clamping rod in the direction of the second clamping rod when the clamping screw is screwed in the threaded bore.
If the material of the shelf boards is sufficiently strong, each clamping rod may be secured with only one fastening screw. The fastening screw is preferably arranged in the center of the clamping rod section which contacts the shelf board, so that forces and torques acting on the connection between the shelf board and the clamping rod can be reliably transmitted. If a fastening screw were located in an end region of the clamping rod, the thread tends to strip.
The clamping rod can be easily and functionally attached by arranging in the shelf board a through-bore and in the clamping rod a threaded bore into which the fastening screw can be inserted.
Although an arrangement where the shelf boards are clamped in the center with two clamping rods located in the center section of the shelf board edges, does not appear to be very stable, it has been found in practice that the shelf boards can absorb large forces. The support rod is formed of a steel tube with an outer diameter of 40 mm and the clamping rods are formed of a stainless steel profile having a square cross-section with lateral sides having a length of 10 mm. The square profiles are embedded in the shelf boards over a length of 60 mm and the free ends of the steel rods project approximately 45 mm from the plane of the shelf board. The shelf boards of this shelf system can easily carry a weight of 80 kg.
The support rods may be attached in a conventional manner (e.g., fastened with screws to a wall, a floor or the ceiling of a room). Alternatively, an advantageous support system is proposed that is under tension and can be easily installed and modified. For this purpose, the support rod is formed as a threaded spindle and includes a tubular jacket with an interior thread and at least one spindle rod which is screwed into the interior thread of the tubular jacket. Respective support plates are arranged on the free end of the spindle rod and on the opposite free end of the support rod, respectively. The support plates can be biased against the floor and the ceiling of a room. These support rods are formed as expanded spindles and can be installed at the different locations of the room independent of the ceiling height. The shelf system can be adapted to different room heights by using tubular jackets of different length.
In a preferred embodiment of the invention, all elements of the support rods are made of stainless steel. The interior thread is formed by a threaded bushing that is inserted into the tubular jacket. The outer circumference of the threaded bushing includes a radial shoulder which contacts the annual end face of the tubular jacket. A small radial threaded bore may be disposed in the wall of the threaded bushing. A set screw may be screwed into the threaded bore to lock the spindle rod, which is screwed into the threaded bushing, in place.
The end of the spindle rod positioned inside the tubular jacket may be provided with a guide disk which is guided inside the tubular jacket essentially without play. The spindle rod is thereby securely held in place inside the tubular jacket in the radial directionxe2x80x94both in the region of the interior thread and in the region of the guide diskxe2x80x94and can reliably absorb transverse forces or torques.
The support plates of the support rods may be pivotally attached to the ends of the support rods by way of ball and socket joints. This smoothes any unevenness in the ceiling and the floor so that the support rods can be positioned in a true vertical direction.
Additional advantages of the invention are described hereinafter with reference to the drawings. The drawings show in: